Linux-grep命令

grep match_pattern file_name 
grep "match_pattern" file_name

grep "match_pattern" file1 file2 ...

grep -v "match_pattern" file_name

grep "match_pattern" file_name --color=auto

grep -E "[1-9]+" 
或 
egrep "[1-9]+"

[root@entel2 test]# echo this is a test line. | grep -o -E "[a-z]+\."
line.

[root@entel2 test]# echo this is a test line. | egrep  -o  "[a-z]+\."
line.

[root@entel2 test]# cat args.txt 
aaa
bbb
ccc
bbb
ddd
aaaaa
[root@entel2 test]# grep -c "aaa" args.txt 
2

[root@entel2 test]# grep -n "aaa" args.txt 
1:aaa
6:aaaaa
[root@entel2 test]# cat args.txt |grep -n "aaa"
1:aaa
6:aaaaa

#多个文件 
grep "match pattern" -n file_1 file_2

[root@entel2 test]# echo gun is not unix | grep -b -o "not"
7:not
[root@entel2 test]# 
[root@entel2 test]# echo gun is not unix | grep -b -o "is"
4:is
[root@entel2 test]# echo gun is not unix | grep -b -o "gun"
0:gun
[root@entel2 test]# echo gun is not unix | grep -b -o "i"
4:i
13:i

[root@entel2 test]# cat grep1.txt 
xiaogongjiang
xiaogongjiang1
[root@entel2 test]# cat grep2.txt 
xiaogongjiang
this is just for test grep -l
[root@entel2 test]# grep -l "xiaogongjiang" grep1.txt  grep2.txt 
grep1.txt
grep2.txt
[root@entel2 test]# grep -l "xiaogongjiang" grep*
grep1.txt
grep2.txt
[root@entel2 test]# grep -l "test" grep*
grep2.txt
[root@entel2 test]# 

# .表示当前目录。
[root@entel2 ~]# grep  "xiaogongjiang"  . -n -r 
./test/grep1.txt:1:xiaogongjiang
./test/grep1.txt:2:xiaogongjiang1
./test/grep2.txt:1:xiaogongjiang

[root@entel2 ~]# echo "hello world" | grep -i "HELLO"
hello world

[root@entel2 ~]# echo this is a text line | grep -e "is" -e "line" -o
is
is
line